Method of forming rims of nonsymmetrical cross-sectional contour



LE JEUNE ET AL 2,139,833

METHOD OF FORMING RIMS OF NONSYMMETRICAL CROSS SECTIONAL CQNTOUR I 2Sheets-Sheet 1 Filed Jan. 6, 1936 11v VENTORS FRANK H. LQJEUNE JOHNE.COPELAND .BY WW/WMMM ATTORNEYS fies. 13, 1938. F. H. LE JEUNE ET AL2,339,833 METHOD OF F ORMING RIMS OF NONSYMMETRICAL CROSS SECTION ALCONTOUR Filed Jan. 6, 1936 2 Sheets-Sheet 2 FHA.

[1V VENTORS FRANK H- LQJ EUNE A TTORNE VS Patented Dec. 13, 1938 UNITEDSTTES ATENT ()FFIQE METHGD F FORMING RIMS OF NONSYM- METRICALCROSS-SECTIONAL CONTOUR aware Application January 6, 1936, Serial No.57.832

5 Claims.

The invention relates to the manufacture of rims and more particularlytire holding rims of that type sometimes designated as peg leg and inwhich the bead seats on opposite sides of the central plane are ofunequal diameter. In the forming of such rims, it is essential thatthese bead seats should be of the proper relative diameters, and wherethe rim is formed by a rolling process this is difficult to accomplish.We have, therefore, devised a process in which the rim seats are firstdie-fashioned to proper relative diameters and subsequently the portionsbetween these seats and outside thereof are refashioned to the desiredcross-sectional contour. The invention, therefore, consists in the novelmethod as hereinafter set forth.

In the drawings:

Figure l is an elevation of, and

Figure 2 is a cross-section through a cylindrical hoop which is to berefashioned into the rim;

Figure 3 is an axial cross-section through the dies for performing thefirst step in the operation;

Figure 4 is a similar view showing the second step;

Figures 5, 6 and 7 are cross-sectional views showing the successivesteps in refashioning the In the forming of rims of symmetricalcrosssection by a rolling process the amount of metal on one side of thecentral plane is more or less in balance with that on the opposite sideso that both sides can be simultaneously refashioned to the desiredcontour. However, in the forming of rims of the so-called peg-legconstruction, there is more metal on one side of the central plane ofthe finished rim than on the other and the radial dimensions are alsodifferent on opposite sides of this plane. This renders it diflicult toaccurately form the rim completely by a rolling process. To overcomethis difficulty, we first fashion the rim by dies so that the portionsthereof which respectively form the bead seats for the opposite sides ofthe tire are of the correct relative diameters. These bead seats arealso positioned so that the metal between the same is sufiicient to formthe drop-center portion of the rim, and the metal on the outer sides isproper for forming the flanges of the rim. .After this preliminaryfashioning operation, the rim is refashioned either by rolling or in anyother suitable manner to obtain the desired cross-section.

As shown in Figures 1 and 2, A is a cylindrical hoop preferably formedin the usual manned by the bending of a rectangular strip of metal intocircular form and uniting the opposite ends thereof by welding. Thishoop is then subjected to a die pressing operation which flares theopposite end portions thereof differentially. Thus, as shown in Figure3, one end of the hoop is engaged with a die member C having acylindrical portion C corresponding to the diameter of the bead seat ofsmaller radius and also having a flaring portion C for initiating theflange on this side of the rim. A second die member D engages theopposite end of the cylindrical hoop and is provided with a flaringportion D of greater length and diameter. In operation, the hoop isfirst engaged with the cylindrical portion C of the die C, after whichthe die D is moved towards the die C by the operation of a plunger E.This will simultaneously expand the portions of the hoop which engagethe flaring portions C and D, the action being limited by stops C and Drespectively at the outer ends of these flaring portions.

After this first operation, the hoop while still in engagement with adie C or a die of corresponding form is subjected to the operation of adie F having a portion F corresponding to the diameter of the bead seatof larger radius and a flaring portion F above the portion F. The lowerend of the die-F is also formed with reverse curves F and F which aretangent to each other and respectively to the portions F and C. Thus, inthe operation of the die F the rim is fashioned to the cross-sectionshown in Figure 4.

The subsequent operations of refashioning the rim are preferablyperformed by complementary rollers. Thus, as shown in Figure 5, therollers G and H fashion the portion of the rim intermediate the beadseats to initiate the dropcenter II. In the next operation shown inFigure 6, the rollers I and J further fashion the drop-center portionand initiate the flanges by the portions J and J In the final operationshown in Figure '7, the rim is brought to the desired cross-sectionalcontour. It is to be noted that during these refashioning operations theportions forming the bead seats remain in the same. relative positionsand are properly spaced upon opposite sides of the central plane of therim. Further finishing operations may be performed on the rim, but theseform no part of the present invention.

What we claim as our invention is:

1. In a method of forming tire rims of nonsymmetrical cross-section, thesteps of die-pressing a cylindrical hoop to differentially flareopposite end portions thereof and to form a bead seat portion adjacentto the smaller flared portion,

further die-fashioning the larger flare portion to expand a sub-portionthereof to the relative diameter of the second bead seat leaving ashoulder between the two bead seat portions and finally refashioning theportions between and on opposite sides of said bead seat portions to thedesired cross-sectional contour.

2. In a method of forming tire rims of nonsymmetrical cross-section, thesteps of die-pressing a cylindrical hoop to differentially flareopposite end portions thereof and to form a bead seat portion adjacentto the smaller flared portion, further die-fashioning the larger flaredportion to expand a sub-portion thereof to the relative diameter of thesecond bead seat leaving a shoulder between the two bead seat portionsand rolling to refashion the portions between and on opposite sides ofsaid bead portions to the desired cross-sectional contour.

3. In a method of forming drop-center tire rims having bead seats ofdifferent radius, the steps of die-pressing a cylindrical hoop todifferentially flare opposite end portions thereof and to form a beadseat portion adjacent to the smaller flared portion, furtherdie-fashioning the larger flared portion to expand a sub-portion thereofto the relative diameter of the second bead seat leaving a shoulder anda portion of the rim between said seats, refashioning the portionbetween said seats to contract the diameter thereof and form thedrop-center or well and refashioning the portions outside said seats toform the rim flanges.

4. In a method of forming drop-center tire rims having bead seats ofdifferent radius, the steps of die-pressing a cylindrical hoop todifferentially flare opposite end portions thereof and to form a beadseat portion adjacent to the smaller flared portion, furtherdie-fashioning the larger flared portion to expand a sub-portion thereofto the relative diameter of a second bead seat leaving a shoulder and aportion of the rim there-between and rolling to refashion the portionbetween said seats contracting the radius thereof to form thedrop-center or well and refashioning the portion outside said seats toform the rim flanges.

5. In a method of forming tire rims of nonsymmetrical cross-section, thesteps of die-pressing a cylindrical hoop to differentially flareopposite end portions thereof and to form bead seat portions ofdifferent diameters with a shoulder therebetween, contracting indiameter the portion between said bead seat portions while maintainingthe latter at substantially their original diameters and expanding theportions, on opposite sides of said bead seat portions to the desiredcross-sectional contour.

FRANK H. LE'JEUNE. JOHN E. COPELAND.

